Ra’avad (Avraham ben David of Posquieres, 12th century) is said to have written commentaries on the entire Talmud, including tractates that exist only as Mishnah. These commentaries include basic explanations as well as more involved analyses and legal conclusions. They were highly respected by other scholars, but few are extant. Of Ra’avad’s commentary on the Mishnah tractate Demai, the third tractate in Zeraim (Agriculture), which discusses how to handle produce from one who is suspected to have neglected tithing, only a few fragments are available.